“We just wanted to do something fun. Something that would make our friends smile and feel really lightweight,” Cselle said. “This is the simplest idea that we could come up with. We literally were just like: What is something that will delight people?”

In DrawChat, you can send friends silly sketches or even draw all over existing photos from your camera. It’s goofy, and a bit reminiscent of DrawSomething, the game that was acquired by Zynga earlier this year in the $180 million OMGPOP deal. But it also feels a bit like Pair as well, since you have these long very, visual records of conversation with friends and family.

Most of my drawings look pretty terrible given the limited screen size and well, the limitations of drawing with your finger. There are different colors to choose from and plenty of backgrounds like photos on the moon and people looking angry or surprised.

The app spreads virally through text messages (not through Facebook yet, since they’re waiting on the social network’s deep integration into iOS 6). If you send a drawing to a friend who doesn’t have the app, they’ll see a preview of the picture and be prompted to download the app.

Cselle has a specialty in mail and messaging after working on Gmail, then enterprise-focused mail startup Xobni, and then his own mail search startup Remail, which was bought by Google. But he’s clearly taking a break from e-mail.

“If you want to build something in e-mail or a new way to handle task management, it’s going to take you a year,” he said. “We wanted to do something quick and fun.”

Indeed. Cselle, Orlow and another co-founder Chloe Bregman built the app in about five weeks from start to finish.